Anyone who has ever used a ladder, especially a long (i.e., forty feet or longer) ladder, has experienced the problems associated with setting the ladder on an uneven surface. Not only is this an onerous problem, it can be dangerous as well if the ladder is not properly leveled. The problems associated with leveling a ladder are exacerbated by long ladders.
Therefore, the art includes many proposals for ensuring a level and stable setting for a ladder. These proposals include extensions for one of the ladder legs, frame units extending through the ladder legs, and the like. While somewhat successful, these devices have several drawbacks which inhibit their commercial acceptance.
For example, many of the prior art devices require modification of the ladder. Therefore, these devices are best mounted on the ladder by the manufacturer. This can increase the cost of the ladder, which can be very detrimental in a highly competitive market such as this one. It also nearly totally precludes an after-market. Such devices also may present storage problems.
Another drawback to many prior art ladder levelers is the difficulty of accurately leveling the ladder. Some devices actually require two people to effect the leveling, and many cannot be leveled while the ladder is in use. Difficulty of use is a major consideration in a market which contains many choices, such as ladders and ladder accessories.
Still another drawback to many prior art ladder levelers is the limited range of adjustment thereof. The range is limited either by the construction or by the inter-relationships of the elements or the stability of the leveler, especially if a long ladder is being leveled. Some ladder levelers cannot be used on stairs because the range of the leveler is not sufficient to compensate for the sharp rise of the stairs coupled with the limited horizontal area available for the feet of the leveler to rest on.
Yet another drawback to many prior art ladder levelers is the lack of support available for the ladder rungs. The present inventor has determined that ladder rungs undergo great stress during use, and such stress may be detrimental, especially if some of the support of the ladder on a leveling device is being produced by the rungs. Any deformation of the rungs may not be desirable.
Still further drawbacks to many prior art ladder levelers is associated with the stability of the leveled ladder. The attachment of the ladder leveling device to the ladder should be as secure as possible in order to increase the safety features of the combination.
Therefore, there is a need for a wide range ladder leveling device that is easily attached to and detached from a ladder without requiring modification of the ladder yet, once attached, will be extremely secure, accurate and stable and will support the rungs of the ladder.